document4
DESCRIPTION
TRANSCRIPT
+
ESS 3092: KINESIOLOGY Week 12
2
+Review
3
+
Name the thigh adductors:
4
+Pectineus
Origin The superior ramus of the
pubis, between the pubic tubercle and the iliopubic eminence
Insertion Pectineal line on the posterior
aspect of the femur
Location Deep
Action Hip adduction Hip internal rotation (weak) Hip flexion (weak)
5
+Adductor Brevis
Origin The body and the inferior
ramus of the pubis
Insertion Pectineal line and the
proximal half of the linea aspera
Location Deep Medial
Posterior to pectineus
Action Hip adduction Hip internal rotation (weak) Hip flexion (weak)
6
+Adductor Longus
Origin The intersection of the
pubic crest and symphysis
Insertion Medial lip of the linea
aspera
Location Medial Superficial
Action Hip adduction Hip flexion
7
+Adductor Magnus
Origin Inferior ramus of the pubis
Insertion Linea aspera to the
adductor tubercle
Location Medial Deepest of the adductors
Action Hip extension Hip adduction (role
unknown)
8
+Gracilis Origin
Thin aponeurosis from the medial surface of the inferior body of the pubis
Insertion Proximal aspect of the medial
surface of the tibia
Location Medial Most superficial of the
adductors
Action Hip adduction Knee flexion Knee internal rotation
9
10
+ The Knee Joint
+ The Knee Joint
Bones & bony landmarks
Joint Structure Ligaments & menisci
Movements
Muscles surrounding the joint & attachments
+Patella
PatellaThe largest sesamoid bone
+Knee Joint
Vulnerable to injury
Provides stability and mobility Extended – joint surfaces congruent Flexed – requires capsule,
ligaments, muscles
3 articulations1)Tibiofemoral (knee)2) Patellofemoral= gliding joint3) Superior tibiofibular
+ 15
Degrees of Freedom
a) Medial/lateral translation
b) Longitudinal rotation
c) Anterior/posterior translation
d) Tibial and femoral rotation
e) Varus/Valgus
f) Flexion/extension
16+Knee Malalignment (Varus ans Valgus)
Hip, knee and ankle should remain in line
Varus moves load medially and increases risk of AO, weight is a confounder increasing risk of AO 5x
Valgus moves load laterally. Less risk of AO compared to varus, but still a factor in AO, minisci, and ligament damage.
+Knee Joint
Bursae (>10) Absorb shock or prevent
friction
Synovial cavity (capsule) Lies under patella &
between surfaces of tibia & femur
Infrapatellar fat pad Posterior to patellar tendon
Osteoarthritis: Breakdown of articular
cartilage– decreased blood supply so does not self-regenerate
+Tibiofemoral Joint
Lateral condyle (c) Flatter, larger surface
area More superior than (b) ↑ stability Aligned w/ femur
Medial condyle (b) Convex Aligned w/ tibia Fits snug with tibia
(concave)
Posterior Anterior
c b
+Tibiofemoral Joint
Menisci form cushions between bones Attached to tibia Enhance stability Thicker outside border
& taper
Medial Larger & more open C
Lateral Closed C configuration
+Tears due to:
Compression & shear forces during rotation while flexing or extending
Quick directional changes in running
Menisectomies ↑ friction 50 % (leads to osteoarthritis)
+ Knee Joint Supporting Ligaments
Cruciate ligaments: (2) ACL & PCL Cross w/in knee between tibia & femur Maintain anterior & posterior stability & rotatory
stability
+Cruciate Ligaments
Posterior Cruciate Ligament (PCL) From posterior middle tibia to anterior medial femoral condyle. Limits posterior movement of tibia on femur PCL injury = direct contact injury
Anterior Cruciate Ligament (ACL) From (anterior) intercondylar eminences of tibia to lateral femoral
condyle Limits anterior movement of tibia on femur Common injury to knee Injury mechanism often involves noncontact rotary forces
Planting & cutting Hyperextension Violent quadriceps contraction (pulls tibia forward on femur)
+ACL Injury
Theories why females tear ACLs 2-7x more than males:
1. ↑ Q-angle in ♀
2. Neurological: when stimulate back of knee, ♀ contract quads, ♂ contract hamstrings.
3. Strength differences: ♂ is stronger than ♀
4. Hormonal: ♀↑ Estrogen => ↑ elasticity => ↑ tearing
+
Lateral (fibular) Collateral Ligament (LCL) Supports knee against varus forces (medial
bending) Laterally directed force
Medial (tibial) Collateral Ligament (MCL) supports knee against valgus forces (lateral
bending) Injuries (contact) are common: more
exposed/vulnerable
Knee Joint Supporting Ligaments
+LCL and MCL
+ Q Angle
Assessment of Lower extremity alignment Patella position
Most efficient angle for quadriceps to function is ~10º Males: 10-14º Females: 15-17º
Genu valgum (knock kneed) > 17º = excessive
Genu varus (bowlegged) Negative
↑ Q angle => ↑ stress on MCL
+ Joint Movements
Flexion (145º ROM) accompanied by internal
rotation (tibia on femur)
Extension (<180º ROM) accompanied by external
rotation (tibia on femur)
+ Joint Movements
External rotation rotary movement of leg laterally
away from midline
Internal rotation rotary movement of lower leg
medially toward midline
Knee must be flexed ≥ 20-30º for motion
30º
45º
+Knee Musculature